Shulou(Shulou.com)06/01 Report--

When the social development enters the "Internet +" era, the traditional PC e-commerce can no longer meet the needs of e-commerce operators, so it is an inevitable trend to create an independent mobile e-commerce system.

With the increasing popularity of mobile e-commerce, many merchants are slowly beginning to join the ranks of mobile e-commerce, so do you know how to design and develop mobile e-commerce system? Yanyu e-commerce to answer questions for you!

1. Planning phase

The main task of the pre-planning stage is to analyze the necessity and feasibility of establishing the database, to determine the status of the database system in the organization and information system, as well as the relationship between the various databases. After the completion of the planning work, a detailed feasibility analysis report and a database system planning outline shall be written. The main contents of the feasibility analysis report include information scope, information sources, human resources, equipment resources, software and support tools resources, development cost estimation, development progress plan, transition plan from current system to new system, etc.

two。 Customer demand stage

In the requirements analysis stage, we should make a comprehensive and detailed investigation of the whole application of the system, determine the goals of the enterprise organization, collect the basic data that support the overall design objectives of the system and the requirements for these data, and determine the needs of users. and write these requirements into documents acceptable to both users and database designers. Analyze the user activity, generate the user activity diagram, that is, the user's business flow chart; determine the system scope, generate the system scope diagram, that is, determine the man-machine interface; analyze the data involved in user activities, and generate data flow diagram. graphically represent the flow direction and processing process of the data; analyze the system data and generate a data dictionary. The key result of this phase is the data flow graph.

3. Conceptual design stage

The goal of conceptual design is to produce the conceptual structure of the database, that is, conceptual schema, which reflects the information needs of enterprise organizations. The conceptual schema is independent of the logical structure of the database and also independent of the supporting database. Conceptual design is the key of the whole database design, and the key achievement of conceptual design stage is the establishment of conceptual data model.

4. Logical design stage

The purpose of logical design is to transform the global conceptual data model designed in the conceptual design phase into a logical structure consistent with the data model supported by DBMS on the selected specific machine, including database schema and external schema. The key achievement of logical design phase is the establishment of logical data model.

5. Physical design phase

Databases are always stored on physical devices. The storage structure and method of a database on a physical device is called the physical structure of a database, which depends on a given computer system. The physical structure of database mainly refers to the storage record format, storage record arrangement and access method of the database. Physical design can be divided into the first three steps involving physical structure design, and the last two steps involving constraints and specific programming.

(1) the design of storage record structure: including the composition of records, the type and length of data items, and the mapping from logical records to storage records.

(2) determine where the data is stored: the data that is often accessed at the same time can be combined.

(3) the design of access method: the access path is divided into main access path and secondary access path, the former is used for primary key retrieval and the latter is used for auxiliary key retrieval.

(4) Integrity and security considerations: designers should analyze and make tradeoffs in terms of integrity, security, effectiveness and efficiency.

(5) programming: after the logical database structure is determined, the application design should begin. The purpose of physical data independence is to eliminate changes to the application caused by changes in the physical structure. Changes to the program may occur when physical independence is not guaranteed. QQ537086251

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